Among other duties, IRBs are charged with protection of vulnerable subjects. A preliminary study showed differences in IRB member judgments of decisional capacity and autonomy related to the primary purpose of the trial (neuropsychiatric versus medical). Participants in hypothetical neuropsychiatric trials were viewed as less capable of providing informed consent than participants in medical trials, even though medical subjects had diagnoses that are frequently associated with neuropsychiatric co-morbidities. The results suggests two processes that could impact IRB protection of human subjects: 1) a tendency to discount decisional vulnerabilities in medical patients, and 2) a potential hyper-sensitivity to such vulnerabilities among neuropsychiatric patients. The proposed study will clarify mechanisms underlying the preliminary findings. Using a systematic, random sample of OHRP-registered IRBs, full members will be randomly selected and asked to evaluate decisional capacity and autonomy for subjects described in a vignettes that are eligible for a clinical trial. Two trials involve health conditions (stage III colon cancer, neuropathic pain). For each health condition, information on depression will be varied to create three levels of depression salience: 1) depression information absent, 2) descriptive depression information present, and 3) descriptive information present with depression as a research parameter. A psychiatric trial for patients with major depression also will be described. We will evaluate 1) whether the inclusion of depression information and its salience affects judgments of decisional capacity for research subjects with medical diagnoses, and 2) whether judgments of participants in psychiatric trials differ from those in the medical trials with depression as a study parameter. A subset of participants in each experimental condition will complete an attitude measure to assess whether psychiatric stigma is associated with evaluations of decisional capacity. Another subset of participants will not receive the stigmatization measure. Judgments of participants who received the measure will be compared to those who did not to determine whether the measure sensitized subjects to psychiatric issues. [unreadable] [unreadable] [unreadable]